MassFLOW-3DTM as a simulation tool for turbidity currents: some preliminary results - From Depositional Systems to Sedimentary Successions on the Norwegian Continental Margin - page 601

(A)

980
976.667
973.333
970
966.667
963.333
960
956.667
953.333
950

(B)

980
976.667
973.333
970
966.667
963.333
960
956.667
953.333
950

RUN 2 RUN 7

250 m 250 m

(C) (D)

velocity drops by more than 50%
due to flow overspill

no significant drop in velocity (15%)

9.5
8.85714
8.21429
7.57143
6.92857
6.28571
5.64286
5
4.35714
3.71429
3.07143
2.42857
1.78571
1. 14286
0.5

9.5
8.85714
8.21429
7.57143
6.92857
6.28571
5.64286
5
4.35714
3.71429
3.07143
2.42857
1.78571
1. 14286
0.5

separation zones
migrate upstream
with falling velocity

separation zones
develop downstream
of bend apexes

250 m 250 m

(E) (F)

1300

1110
1105
1100
1095
1090
1085
1080
1075
1070
1065
1060
1055
1050
1045
1040

1281.43
1262.86
1244.29
1225.71
1207.14
1188.57
1170
1151.43
1132.86
1114.29
1095.71
1077.14
1058.57
1040

high-density
core centered
around bend apex

density increase
irrespective of
separation zone

density increase
irrespective of
separation zone

250 m 250 m

Fig. 13. Comparison of flow height, velocity and concentration levels between Run 2 and Run 7. (A) In Run 2, the flow
experiences immense overspill at Bend 1 leading to significant reduction of flow height in Bend 2. (B) In Run 7, the over-
spill and its effect on flow height is reduced. Note the sup elevation of the flow at channel bends in both A and B. Flow
surface visualised at 20% vol. concentration. (C) Slice 4 m above the channel floor showing velocity magnitude in Run 2.
Overspill at Bend 1 reduces velocity of the remaining channelised flow by more than 50%. The high-velocity core travels
attached to the outer banks developing low-velocity separation zones downstream of bend apexes. The velocity field in
Bend 3 is greatly influenced by the re-entry of the overbank flow into the channel. (D) Slice 4 m above the channel floor
showing velocity magnitude in Run 7. No significant reduction in velocity occurs downstream of Bend 1. Separation zones
develop further upstream than in Run 2. The velocity field in Bend 3 does not seem to be affected by the overbank flow. (E, F)
Density (concentration) slices at 4 m above the channel floor. The velocity separation zones do not seem to have an effect
on the density levels, suggesting separation zones with high concentrations are prone to increased deposition. The high-
density core in Run 7 appears to be more centred around the bend apex than that in Run 2.